[F16bmathis]

I'm helping some guys build a 144V 500 amp EV (Chevy S10) and they want a HV Disconnect Switch.

I'm pretty sure I bought the one at cloudelectric, http://www.cloudelectric.com/product_p/sw-20259.htm but it says its a 5000 amp at 12V, or 2500 amp at 24V, or.....

Is this the proper switch to disconnect main power?

 

[EVfun]

I'm not seeing any rating that would indicate it can interrupt high DC voltages, so I suspect it isn't suitable as a HV disconnect.

 

[EV-propulsion.com]

These are available,

limited by the anderson connector rating. Rating can be found here: http://www.andersonpower.com/products/multipole-sb.html


and these that are rated at 145 v DC and 600 amps, which also hold a fuse.

Both are relatively large compared to the little switch that you mentioned, which in my opinion is NOT anywhere near rated for high voltage DC. The problem with using a switch rated for low voltage in a high voltage system is if switched under load, the voltage can arc between the contacts and continue the current flow (plasma ball style) possibly making a bad situation worse.
Mike
www.EV-propulsion.com

 

[brainzel]

Take a look at these battery switches from BepMarine:

There are several switches with different ratings available.

 

[F16bmathis]

I'm not seeing any rating that would indicate it can interrupt high DC voltages, so I suspect it isn't suitable as a HV disconnect.

I know! I had bought this disconnect as part of a kit that was made years ago. I don't remember who designed the kit, and I've been using the switch for years, even had a Zilla and a Curtis go up in smoke, and both times that disconnect switch was then turned off. The Zilla died and that was that, when the Curtis blew, I started going for a ride till I turned off my key and pulled that disconnect switch.

I guess I could try putting a few hundred amps through it and disconnect it to see if it does actually work...

Do most people not use a HV disconnect? Or maybe this is meant for disconnecting while working on the vehicle. I've got over 15,000 miles on this switch!

 

[dtbaker]

I'm helping some guys build a 144V 500 amp EV (Chevy S10) and they want a HV Disconnect Switch.

I'm pretty sure I bought the one at cloudelectric, http://www.cloudelectric.com/product_p/sw-20259.htm but it says its a 5000 amp at 12V, or 2500 amp at 24V, or.....

Is this the proper switch to disconnect main power?

this is really NOT appropriate, and may not work if you pulled it under load due to arcing.

Do you have a main circuit breaker (you should!). A big fat GE or Airpax rated to interrupt 500amps at 250vDC ? you can rig a choke cable pull from the cabin..... or use a big fat anderson at the very least.

 

[mizlplix]

The one you reference to is a battery disconnect. Not an emergency interrupt. It will arc under a high amperage/high voltage disconnect. Even an Anderson will arc under a loaded disconnect, they open way too slow.

Anything that will not snap open, will arc under load (and even some of those do too).

For an emergency disconnect, there are two schools of thought:

Buy a large, correctly rated switch or breaker (expensive).

Buy one with the right amp rating, but lower voltage rating (like the one mentioned) and make a way to remotely disconnect it. If it is used under a full load, The switch will be sacrificial in that instance. Just have it in a spot where a possible large smoking hole will not be a problem...LOL

Both will save the car.

I have two of the BEP Marine types, rated at 650 amps continuous. One before my contactor with a 10" dielectric handle, one between battery packs, for maintenance safety.

 

[Gozer]

I am currently putting in the anderson disconnect and wondered if disconnecting the positive run in the connector would be adequate. I would leave the negative run from the battery teminal to the controller.

 

[Guest]

I'm helping some guys build a 144V 500 amp EV (Chevy S10) and they want a HV Disconnect Switch.

I'm pretty sure I bought the one at cloudelectric, http://www.cloudelectric.com/product_p/sw-20259.htm but it says its a 5000 amp at 12V, or 2500 amp at 24V, or.....

Is this the proper switch to disconnect main power?

These are basically just a battery shut off and not meant for HV disconnect under loads. They are great for disabling the main pack when you leave the car for any time. It will shut off power to every thing. But not a load shut off.

Pete

 

[mizlplix]

If you have ever flipped a circuit breaker on-off-on-off, and noticed it makes a snapping sound? It is because it connects/disconnects very quickly to minimize arcing.

Anything interrupting a closed, operating, loaded circuit will arc. The faster it gets done and the farther the contacts are apart, the less the arcing will be.

A 100 Amp switch rated for 600 volts will have the contacts farther apart than a 100 Amp switch rated for 60 volts. Even though they both will carry the same 100 Amps.

No matter what the rating, anything opening slowly under load will arc.

 

[greif]

so if you have a 48v 500 amp controller you should have at least a 48v 500 amp dc breaker?

 

[green caveman]

If we're talking emergency disconnects then there's a thread on this. jackbauer suggested the kilovac ev200 You get to break 2000A, 320V. You can only do this once (but, obviously you can make/break many cycles at lower power).

There's also a suggestion from Dan Baker to use an inertial fuel shutoff switch so that you'll drop power if you crash.
http://relays.tycoelectronics.com/datasheets/ev200.pdf

 

[mizlplix]

In theory, yes. Everything electrical needs to be up to the system rating.

(in theory)......my emergency disconnect is rated at 600 amps continuously . It is rated at 48vdc and I am running 120vdc. It has a dielectric handle for that once in an emergency full power disconnect. Because it is going to make a mess....It is in a place where it will cause minimal harm and easy to put out the fire. (but remember, you are stopping from having a greater problem.)

My old jet electrica had for a disconnect, a vise grip looking deal with copper contacts and a choke cable for remote operation. Not good either and it was a factory affair. You could even make one of those easily.

In my opinion, all emergency disconnects need to be manual, not electric.

And I might take some heat from the forum members, but an Anderson plug is just that.....a plug. Not a good disconnect. They will get damaged if opened under load, even with that fancy unplugging contraption.

It is like unplugging your welder when a rod is stuck. Not a wise thing to do.

Whatever you use must meet the amperage rating of your motor. It needs to be accessible and marked. A red handle is nice too.

 

[cruisin]

If you have ever flipped a circuit breaker on-off-on-off, and noticed it makes a snapping sound? It is because it connects/disconnects very quickly to minimize arcing.

Anything interrupting a closed, operating, loaded circuit will arc. The faster it gets done and the farther the contacts are apart, the less the arcing will be.

A 100 Amp switch rated for 600 volts will have the contacts farther apart than a 100 Amp switch rated for 60 volts. Even though they both will carry the same 100 Amps.

No matter what the rating, anything opening slowly under load will arc.

Here is what you need available in classifieds

 

[m38mike]

In my EV I installed an industrial breaker rated at 160vdc and 600amps. It cost me about $300 for the breaker and another $20 or so for the housing and hardware to mount it. Here's how I mounted it.

The cables enter from either end of the 2" pull box and bolt directly to the breaker. I cut a slot in the cover for the breaker lever to stick out. For operation in a remote location, a hole could be drilled in the lever, and a cable attached that could pull the breaker to disconnect power.

I use this as my master shutoff when I'm not using the EV. My charger bypasses this switch so I can still charge the pack with this breaker off.

 

[dtbaker]

If we're talking emergency disconnects then there's a thread on this. jackbauer suggested the kilovac ev200 You get to break 2000A, 320V. You can only do this once (but, obviously you can make/break many cycles at lower power).

Kilovac is good as a main contactor, but you STILL should have a manual pull circuit breaker.

There's also a suggestion from Dan Baker to use an inertial fuel shutoff switch so that you'll drop power if you crash.

inertia switch is good idea in case of accident, but you STILL should have a manual pull circuit breaker because it only cuts the 12v power to your main contactor which could potentially be welded shut.

 

[mcbrems]

Well, I ended up buying the Albright ED250B, with magnetic blowouts:

http://www.cloudelectric.com/product-p/sw-ed250b.htm

It's a great buy - Don't know what Cloud Electric has up their sleeve.
The switch is very beefy, and will easily accept 1/0 or 2/0 cable with
5/16" lugs. It also snaps quite well when operated. The switch is ON
when pulled out, and disconnected when pushed.

I was planning to mount in my center console, at the bottom, just in
front of the shifter boot. It will be breaking the cable that joins the front
and rear packs as it travels up the tunnel. It won't require a large hole
in the console panel to mount.

So far so good. I was pleased that the switch was hefty, but didn't expect
the button to be so large. It's like a sizable clown nose - 3 to 4 inches
in diameter. It screws onto the switch shaft with an 8mm thread (Albright
is British).

I hope you've been entertained thus far. The question is whether anybody
knows of a source for 8mm thread clown noses that are maybe half
this size. Maybe something that will look more James Bond-ish on my
console.

Cheers,
McB

 

[Ziggythewiz]

You might want to rethink the location for that, especially if you want to make the shroom smaller. Mine is on the dash to the left of the steering wheel so an emergency responder can easily see and get to it.

 

[Ivansgarage]

This is what i used for a em. disconnect 53 bucks. Got a pull cable going up to the dash. I took this all apart to check
it out, it is very heavy duty contacts and well made.

http://www.newagemarine.com/bep720.html

Ivansgarage Electric Sonoma
http://ivanbennett.com/

 

[swoozle]

This is what i used for a em. disconnect 53 bucks. Got a pull cable going up to the dash. I took this all apart to check
it out, it is very heavy duty contacts and well made.

http://www.newagemarine.com/bep720.html

I've got the same one for use as a maintenance disconnect, but can you really rely on it to disconnect under load? It didn't look like there was anything special in there to keep it from arcing and welding shut.